mirror of
https://github.com/kanjitalk755/macemu.git
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46dc8c5391
range. This is a configure-time safety net that depends on the GCC "Labels as Values" extension.
1284 lines
39 KiB
C++
1284 lines
39 KiB
C++
/*
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* sigsegv.cpp - SIGSEGV signals support
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*
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* Derived from Bruno Haible's work on his SIGSEGV library for clisp
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* <http://clisp.sourceforge.net/>
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*
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* MacOS X support derived from the post by Timothy J. Wood to the
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* omnigroup macosx-dev list:
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* Mach Exception Handlers 101 (Was Re: ptrace, gdb)
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* tjw@omnigroup.com Sun, 4 Jun 2000
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* www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html
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*
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* Basilisk II (C) 1997-2002 Christian Bauer
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifdef HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <list>
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#include <signal.h>
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#include "sigsegv.h"
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#ifndef NO_STD_NAMESPACE
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using std::list;
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#endif
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// Return value type of a signal handler (standard type if not defined)
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#ifndef RETSIGTYPE
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#define RETSIGTYPE void
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#endif
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// Type of the system signal handler
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typedef RETSIGTYPE (*signal_handler)(int);
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// User's SIGSEGV handler
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static sigsegv_fault_handler_t sigsegv_fault_handler = 0;
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// Function called to dump state if we can't handle the fault
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static sigsegv_state_dumper_t sigsegv_state_dumper = 0;
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// Actual SIGSEGV handler installer
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static bool sigsegv_do_install_handler(int sig);
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/*
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* Instruction decoding aids
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*/
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// Transfer size
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enum transfer_size_t {
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SIZE_UNKNOWN,
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SIZE_BYTE,
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SIZE_WORD,
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SIZE_LONG
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};
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// Transfer type
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typedef sigsegv_transfer_type_t transfer_type_t;
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#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
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// Addressing mode
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enum addressing_mode_t {
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MODE_UNKNOWN,
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MODE_NORM,
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MODE_U,
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MODE_X,
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MODE_UX
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};
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// Decoded instruction
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struct instruction_t {
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transfer_type_t transfer_type;
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transfer_size_t transfer_size;
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addressing_mode_t addr_mode;
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unsigned int addr;
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char ra, rd;
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};
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static void powerpc_decode_instruction(instruction_t *instruction, unsigned int nip, unsigned int * gpr)
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{
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// Get opcode and divide into fields
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unsigned int opcode = *((unsigned int *)nip);
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unsigned int primop = opcode >> 26;
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unsigned int exop = (opcode >> 1) & 0x3ff;
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unsigned int ra = (opcode >> 16) & 0x1f;
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unsigned int rb = (opcode >> 11) & 0x1f;
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unsigned int rd = (opcode >> 21) & 0x1f;
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signed int imm = (signed short)(opcode & 0xffff);
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// Analyze opcode
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transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
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transfer_size_t transfer_size = SIZE_UNKNOWN;
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addressing_mode_t addr_mode = MODE_UNKNOWN;
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switch (primop) {
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case 31:
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switch (exop) {
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case 23: // lwzx
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
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case 55: // lwzux
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
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case 87: // lbzx
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
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case 119: // lbzux
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
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case 151: // stwx
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
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case 183: // stwux
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
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case 215: // stbx
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
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case 247: // stbux
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
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case 279: // lhzx
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
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case 311: // lhzux
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
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case 343: // lhax
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
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case 375: // lhaux
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
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case 407: // sthx
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
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case 439: // sthux
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
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}
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break;
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case 32: // lwz
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
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case 33: // lwzu
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
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case 34: // lbz
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
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case 35: // lbzu
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
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case 36: // stw
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
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case 37: // stwu
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
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case 38: // stb
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
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case 39: // stbu
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
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case 40: // lhz
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
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case 41: // lhzu
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
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case 42: // lha
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
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case 43: // lhau
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
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case 44: // sth
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
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case 45: // sthu
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
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}
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// Calculate effective address
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unsigned int addr = 0;
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switch (addr_mode) {
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case MODE_X:
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case MODE_UX:
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if (ra == 0)
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addr = gpr[rb];
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else
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addr = gpr[ra] + gpr[rb];
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break;
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case MODE_NORM:
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case MODE_U:
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if (ra == 0)
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addr = (signed int)(signed short)imm;
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else
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addr = gpr[ra] + (signed int)(signed short)imm;
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break;
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default:
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break;
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}
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// Commit decoded instruction
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instruction->addr = addr;
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instruction->addr_mode = addr_mode;
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instruction->transfer_type = transfer_type;
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instruction->transfer_size = transfer_size;
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instruction->ra = ra;
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instruction->rd = rd;
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}
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#endif
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/*
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* OS-dependant SIGSEGV signals support section
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*/
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#if HAVE_SIGINFO_T
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// Generic extended signal handler
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#define SIGSEGV_FAULT_HANDLER sigsegv_fault_handler
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#if defined(__NetBSD__) || defined(__FreeBSD__)
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
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#else
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#endif
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, sip, scp
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#define SIGSEGV_FAULT_ADDRESS sip->si_addr
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#if defined(__NetBSD__) || defined(__FreeBSD__)
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#if (defined(i386) || defined(__i386__))
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#define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_eip)
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#define SIGSEGV_REGISTER_FILE ((unsigned int *)&(((struct sigcontext *)scp)->sc_edi)) /* EDI is the first GPR (even below EIP) in sigcontext */
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#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
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#endif
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#endif
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#if defined(__linux__)
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#if (defined(i386) || defined(__i386__))
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#include <sys/ucontext.h>
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#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
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#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[14] /* should use REG_EIP instead */
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#define SIGSEGV_REGISTER_FILE (unsigned int *)SIGSEGV_CONTEXT_REGS
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#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
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#endif
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#if (defined(x86_64) || defined(__x86_64__))
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#include <sys/ucontext.h>
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#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
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#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[16] /* should use REG_RIP instead */
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#define SIGSEGV_REGISTER_FILE (unsigned long *)SIGSEGV_CONTEXT_REGS
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#endif
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#if (defined(ia64) || defined(__ia64__))
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#define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */
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#endif
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#if (defined(powerpc) || defined(__powerpc__))
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#include <sys/ucontext.h>
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#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.regs)
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#define SIGSEGV_FAULT_INSTRUCTION (SIGSEGV_CONTEXT_REGS->nip)
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#define SIGSEGV_REGISTER_FILE (unsigned int *)&SIGSEGV_CONTEXT_REGS->nip, (unsigned int *)(SIGSEGV_CONTEXT_REGS->gpr)
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#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
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#endif
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#endif
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#endif
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#if HAVE_SIGCONTEXT_SUBTERFUGE
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#define SIGSEGV_FAULT_HANDLER sigsegv_fault_handler
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// Linux kernels prior to 2.4 ?
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#if defined(__linux__)
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#if (defined(i386) || defined(__i386__))
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#include <asm/sigcontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, scs
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#define SIGSEGV_FAULT_ADDRESS scs.cr2
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#define SIGSEGV_FAULT_INSTRUCTION scs.eip
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#define SIGSEGV_REGISTER_FILE (unsigned int *)(&scs)
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#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
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#endif
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#if (defined(sparc) || defined(__sparc__))
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#include <asm/sigcontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp, addr
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#define SIGSEGV_FAULT_ADDRESS addr
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#endif
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#if (defined(powerpc) || defined(__powerpc__))
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#include <asm/sigcontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, scp
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#define SIGSEGV_FAULT_ADDRESS scp->regs->dar
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#define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip
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#define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->regs->nip, (unsigned int *)(scp->regs->gpr)
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#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
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#endif
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#if (defined(alpha) || defined(__alpha__))
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#include <asm/sigcontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
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#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
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#define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc
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// From Boehm's GC 6.0alpha8
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static sigsegv_address_t get_fault_address(struct sigcontext *scp)
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{
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unsigned int instruction = *((unsigned int *)(scp->sc_pc));
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unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
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fault_address += (signed long)(signed short)(instruction & 0xffff);
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return (sigsegv_address_t)fault_address;
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}
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#endif
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#endif
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// Irix 5 or 6 on MIPS
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#if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
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#include <ucontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
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#define SIGSEGV_FAULT_ADDRESS scp->sc_badvaddr
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#endif
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// HP-UX
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#if (defined(hpux) || defined(__hpux__))
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
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#define SIGSEGV_FAULT_ADDRESS scp->sc_sl.sl_ss.ss_narrow.ss_cr21
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) FAULT_HANDLER(SIGBUS)
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#endif
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// OSF/1 on Alpha
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#if defined(__osf__)
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#include <ucontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
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#define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#endif
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// AIX
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#if defined(_AIX)
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
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#define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#endif
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// NetBSD or FreeBSD
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#if defined(__NetBSD__) || defined(__FreeBSD__)
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#if (defined(m68k) || defined(__m68k__))
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#include <m68k/frame.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
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#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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// Use decoding scheme from BasiliskII/m68k native
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static sigsegv_address_t get_fault_address(struct sigcontext *scp)
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{
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struct sigstate {
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int ss_flags;
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struct frame ss_frame;
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};
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struct sigstate *state = (struct sigstate *)scp->sc_ap;
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char *fault_addr;
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switch (state->ss_frame.f_format) {
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case 7: /* 68040 access error */
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/* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */
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fault_addr = state->ss_frame.f_fmt7.f_fa;
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break;
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default:
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fault_addr = (char *)code;
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break;
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}
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return (sigsegv_address_t)fault_addr;
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}
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#else
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, void *scp, char *addr
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp, addr
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#define SIGSEGV_FAULT_ADDRESS addr
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
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#endif
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#endif
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// MacOS X, not sure which version this works in. Under 10.1
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// vm_protect does not appear to work from a signal handler. Under
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// 10.2 signal handlers get siginfo type arguments but the si_addr
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// field is the address of the faulting instruction and not the
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// address that caused the SIGBUS. Maybe this works in 10.0? In any
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// case with Mach exception handlers there is a way to do what this
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// was meant to do.
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#ifndef HAVE_MACH_EXCEPTIONS
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#if defined(__APPLE__) && defined(__MACH__)
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#if (defined(ppc) || defined(__ppc__))
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
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#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
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#define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
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#define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->sc_ir, &((unsigned int *) scp->sc_regs)[2]
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#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
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// Use decoding scheme from SheepShaver
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static sigsegv_address_t get_fault_address(struct sigcontext *scp)
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{
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unsigned int nip = (unsigned int) scp->sc_ir;
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unsigned int * gpr = &((unsigned int *) scp->sc_regs)[2];
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instruction_t instr;
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powerpc_decode_instruction(&instr, nip, gpr);
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return (sigsegv_address_t)instr.addr;
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}
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#endif
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#endif
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#endif
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#endif
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#if HAVE_MACH_EXCEPTIONS
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// This can easily be extended to other Mach systems, but really who
|
|
// uses HURD (oops GNU/HURD), Darwin/x86, NextStep, Rhapsody, or CMU
|
|
// Mach 2.5/3.0?
|
|
#if defined(__APPLE__) && defined(__MACH__)
|
|
|
|
#include <sys/types.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <pthread.h>
|
|
|
|
/*
|
|
* If you are familiar with MIG then you will understand the frustration
|
|
* that was necessary to get these embedded into C++ code by hand.
|
|
*/
|
|
extern "C" {
|
|
#include <mach/mach.h>
|
|
#include <mach/mach_error.h>
|
|
|
|
extern boolean_t exc_server(mach_msg_header_t *, mach_msg_header_t *);
|
|
extern kern_return_t catch_exception_raise(mach_port_t, mach_port_t,
|
|
mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t);
|
|
extern kern_return_t exception_raise(mach_port_t, mach_port_t, mach_port_t,
|
|
exception_type_t, exception_data_t, mach_msg_type_number_t);
|
|
extern kern_return_t exception_raise_state(mach_port_t, exception_type_t,
|
|
exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
|
|
thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
|
|
extern kern_return_t exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
|
|
exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
|
|
thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
|
|
}
|
|
|
|
// Could make this dynamic by looking for a result of MIG_ARRAY_TOO_LARGE
|
|
#define HANDLER_COUNT 64
|
|
|
|
// structure to tuck away existing exception handlers
|
|
typedef struct _ExceptionPorts {
|
|
mach_msg_type_number_t maskCount;
|
|
exception_mask_t masks[HANDLER_COUNT];
|
|
exception_handler_t handlers[HANDLER_COUNT];
|
|
exception_behavior_t behaviors[HANDLER_COUNT];
|
|
thread_state_flavor_t flavors[HANDLER_COUNT];
|
|
} ExceptionPorts;
|
|
|
|
// exception handler thread
|
|
static pthread_t exc_thread;
|
|
|
|
// place where old exception handler info is stored
|
|
static ExceptionPorts ports;
|
|
|
|
// our exception port
|
|
static mach_port_t _exceptionPort = MACH_PORT_NULL;
|
|
|
|
#define MACH_CHECK_ERROR(name,ret) \
|
|
if (ret != KERN_SUCCESS) { \
|
|
mach_error(#name, ret); \
|
|
exit (1); \
|
|
}
|
|
|
|
#define SIGSEGV_FAULT_ADDRESS code[1]
|
|
#define SIGSEGV_FAULT_INSTRUCTION get_fault_instruction(thread, state)
|
|
#define SIGSEGV_FAULT_HANDLER (code[0] == KERN_PROTECTION_FAILURE) && sigsegv_fault_handler
|
|
#define SIGSEGV_FAULT_HANDLER_ARGLIST mach_port_t thread, exception_data_t code, ppc_thread_state_t *state
|
|
#define SIGSEGV_FAULT_HANDLER_ARGS thread, code, &state
|
|
#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
|
|
#define SIGSEGV_REGISTER_FILE &state->srr0, &state->r0
|
|
|
|
// Given a suspended thread, stuff the current instruction and
|
|
// registers into state.
|
|
//
|
|
// It would have been nice to have this be ppc/x86 independant which
|
|
// could have been done easily with a thread_state_t instead of
|
|
// ppc_thread_state_t, but because of the way this is called it is
|
|
// easier to do it this way.
|
|
#if (defined(ppc) || defined(__ppc__))
|
|
static inline sigsegv_address_t get_fault_instruction(mach_port_t thread, ppc_thread_state_t *state)
|
|
{
|
|
kern_return_t krc;
|
|
mach_msg_type_number_t count;
|
|
|
|
count = MACHINE_THREAD_STATE_COUNT;
|
|
krc = thread_get_state(thread, MACHINE_THREAD_STATE, (thread_state_t)state, &count);
|
|
MACH_CHECK_ERROR (thread_get_state, krc);
|
|
|
|
return (sigsegv_address_t)state->srr0;
|
|
}
|
|
#endif
|
|
|
|
// Since there can only be one exception thread running at any time
|
|
// this is not a problem.
|
|
#define MSG_SIZE 512
|
|
static char msgbuf[MSG_SIZE];
|
|
static char replybuf[MSG_SIZE];
|
|
|
|
/*
|
|
* This is the entry point for the exception handler thread. The job
|
|
* of this thread is to wait for exception messages on the exception
|
|
* port that was setup beforehand and to pass them on to exc_server.
|
|
* exc_server is a MIG generated function that is a part of Mach.
|
|
* Its job is to decide what to do with the exception message. In our
|
|
* case exc_server calls catch_exception_raise on our behalf. After
|
|
* exc_server returns, it is our responsibility to send the reply.
|
|
*/
|
|
static void *
|
|
handleExceptions(void *priv)
|
|
{
|
|
mach_msg_header_t *msg, *reply;
|
|
kern_return_t krc;
|
|
|
|
msg = (mach_msg_header_t *)msgbuf;
|
|
reply = (mach_msg_header_t *)replybuf;
|
|
|
|
for (;;) {
|
|
krc = mach_msg(msg, MACH_RCV_MSG, MSG_SIZE, MSG_SIZE,
|
|
_exceptionPort, 0, MACH_PORT_NULL);
|
|
MACH_CHECK_ERROR(mach_msg, krc);
|
|
|
|
if (!exc_server(msg, reply)) {
|
|
fprintf(stderr, "exc_server hated the message\n");
|
|
exit(1);
|
|
}
|
|
|
|
krc = mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0,
|
|
msg->msgh_local_port, 0, MACH_PORT_NULL);
|
|
if (krc != KERN_SUCCESS) {
|
|
fprintf(stderr, "Error sending message to original reply port, krc = %d, %s",
|
|
krc, mach_error_string(krc));
|
|
exit(1);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
|
|
/*
|
|
* Instruction skipping
|
|
*/
|
|
|
|
#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
|
|
// Decode and skip X86 instruction
|
|
#if (defined(i386) || defined(__i386__))
|
|
#if defined(__linux__)
|
|
enum {
|
|
X86_REG_EIP = 14,
|
|
X86_REG_EAX = 11,
|
|
X86_REG_ECX = 10,
|
|
X86_REG_EDX = 9,
|
|
X86_REG_EBX = 8,
|
|
X86_REG_ESP = 7,
|
|
X86_REG_EBP = 6,
|
|
X86_REG_ESI = 5,
|
|
X86_REG_EDI = 4
|
|
};
|
|
#endif
|
|
#if defined(__NetBSD__) || defined(__FreeBSD__)
|
|
enum {
|
|
X86_REG_EIP = 10,
|
|
X86_REG_EAX = 7,
|
|
X86_REG_ECX = 6,
|
|
X86_REG_EDX = 5,
|
|
X86_REG_EBX = 4,
|
|
X86_REG_ESP = 13,
|
|
X86_REG_EBP = 2,
|
|
X86_REG_ESI = 1,
|
|
X86_REG_EDI = 0
|
|
};
|
|
#endif
|
|
// FIXME: this is partly redundant with the instruction decoding phase
|
|
// to discover transfer type and register number
|
|
static inline int ix86_step_over_modrm(unsigned char * p)
|
|
{
|
|
int mod = (p[0] >> 6) & 3;
|
|
int rm = p[0] & 7;
|
|
int offset = 0;
|
|
|
|
// ModR/M Byte
|
|
switch (mod) {
|
|
case 0: // [reg]
|
|
if (rm == 5) return 4; // disp32
|
|
break;
|
|
case 1: // disp8[reg]
|
|
offset = 1;
|
|
break;
|
|
case 2: // disp32[reg]
|
|
offset = 4;
|
|
break;
|
|
case 3: // register
|
|
return 0;
|
|
}
|
|
|
|
// SIB Byte
|
|
if (rm == 4) {
|
|
if (mod == 0 && (p[1] & 7) == 5)
|
|
offset = 5; // disp32[index]
|
|
else
|
|
offset++;
|
|
}
|
|
|
|
return offset;
|
|
}
|
|
|
|
static bool ix86_skip_instruction(unsigned int * regs)
|
|
{
|
|
unsigned char * eip = (unsigned char *)regs[X86_REG_EIP];
|
|
|
|
if (eip == 0)
|
|
return false;
|
|
|
|
transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
|
|
transfer_size_t transfer_size = SIZE_LONG;
|
|
|
|
int reg = -1;
|
|
int len = 0;
|
|
|
|
// Operand size prefix
|
|
if (*eip == 0x66) {
|
|
eip++;
|
|
len++;
|
|
transfer_size = SIZE_WORD;
|
|
}
|
|
|
|
// Decode instruction
|
|
switch (eip[0]) {
|
|
case 0x0f:
|
|
switch (eip[1]) {
|
|
case 0xb6: // MOVZX r32, r/m8
|
|
case 0xb7: // MOVZX r32, r/m16
|
|
switch (eip[2] & 0xc0) {
|
|
case 0x80:
|
|
reg = (eip[2] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_LOAD;
|
|
break;
|
|
case 0x40:
|
|
reg = (eip[2] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_LOAD;
|
|
break;
|
|
case 0x00:
|
|
reg = (eip[2] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_LOAD;
|
|
break;
|
|
}
|
|
len += 3 + ix86_step_over_modrm(eip + 2);
|
|
break;
|
|
}
|
|
break;
|
|
case 0x8a: // MOV r8, r/m8
|
|
transfer_size = SIZE_BYTE;
|
|
case 0x8b: // MOV r32, r/m32 (or 16-bit operation)
|
|
switch (eip[1] & 0xc0) {
|
|
case 0x80:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_LOAD;
|
|
break;
|
|
case 0x40:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_LOAD;
|
|
break;
|
|
case 0x00:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_LOAD;
|
|
break;
|
|
}
|
|
len += 2 + ix86_step_over_modrm(eip + 1);
|
|
break;
|
|
case 0x88: // MOV r/m8, r8
|
|
transfer_size = SIZE_BYTE;
|
|
case 0x89: // MOV r/m32, r32 (or 16-bit operation)
|
|
switch (eip[1] & 0xc0) {
|
|
case 0x80:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_STORE;
|
|
break;
|
|
case 0x40:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_STORE;
|
|
break;
|
|
case 0x00:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = SIGSEGV_TRANSFER_STORE;
|
|
break;
|
|
}
|
|
len += 2 + ix86_step_over_modrm(eip + 1);
|
|
break;
|
|
}
|
|
|
|
if (transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
|
|
// Unknown machine code, let it crash. Then patch the decoder
|
|
return false;
|
|
}
|
|
|
|
if (transfer_type == SIGSEGV_TRANSFER_LOAD && reg != -1) {
|
|
static const int x86_reg_map[8] = {
|
|
X86_REG_EAX, X86_REG_ECX, X86_REG_EDX, X86_REG_EBX,
|
|
X86_REG_ESP, X86_REG_EBP, X86_REG_ESI, X86_REG_EDI
|
|
};
|
|
|
|
if (reg < 0 || reg >= 8)
|
|
return false;
|
|
|
|
int rloc = x86_reg_map[reg];
|
|
switch (transfer_size) {
|
|
case SIZE_BYTE:
|
|
regs[rloc] = (regs[rloc] & ~0xff);
|
|
break;
|
|
case SIZE_WORD:
|
|
regs[rloc] = (regs[rloc] & ~0xffff);
|
|
break;
|
|
case SIZE_LONG:
|
|
regs[rloc] = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
#if DEBUG
|
|
printf("%08x: %s %s access", regs[X86_REG_EIP],
|
|
transfer_size == SIZE_BYTE ? "byte" : transfer_size == SIZE_WORD ? "word" : "long",
|
|
transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
|
|
|
|
if (reg != -1) {
|
|
static const char * x86_reg_str_map[8] = {
|
|
"eax", "ecx", "edx", "ebx",
|
|
"esp", "ebp", "esi", "edi"
|
|
};
|
|
printf(" %s register %%%s", transfer_type == SIGSEGV_TRANSFER_LOAD ? "to" : "from", x86_reg_str_map[reg]);
|
|
}
|
|
printf(", %d bytes instruction\n", len);
|
|
#endif
|
|
|
|
regs[X86_REG_EIP] += len;
|
|
return true;
|
|
}
|
|
#endif
|
|
|
|
// Decode and skip PPC instruction
|
|
#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
|
|
static bool powerpc_skip_instruction(unsigned int * nip_p, unsigned int * regs)
|
|
{
|
|
instruction_t instr;
|
|
powerpc_decode_instruction(&instr, *nip_p, regs);
|
|
|
|
if (instr.transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
|
|
// Unknown machine code, let it crash. Then patch the decoder
|
|
return false;
|
|
}
|
|
|
|
#if DEBUG
|
|
printf("%08x: %s %s access", *nip_p,
|
|
instr.transfer_size == SIZE_BYTE ? "byte" : instr.transfer_size == SIZE_WORD ? "word" : "long",
|
|
instr.transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
|
|
|
|
if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
|
|
printf(" r%d (ra = %08x)\n", instr.ra, instr.addr);
|
|
if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
|
|
printf(" r%d (rd = 0)\n", instr.rd);
|
|
#endif
|
|
|
|
if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
|
|
regs[instr.ra] = instr.addr;
|
|
if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
|
|
regs[instr.rd] = 0;
|
|
|
|
*nip_p += 4;
|
|
return true;
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
// Fallbacks
|
|
#ifndef SIGSEGV_FAULT_INSTRUCTION
|
|
#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC
|
|
#endif
|
|
|
|
// SIGSEGV recovery supported ?
|
|
#if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
|
|
#define HAVE_SIGSEGV_RECOVERY
|
|
#endif
|
|
|
|
|
|
/*
|
|
* SIGSEGV global handler
|
|
*/
|
|
|
|
#if defined(HAVE_SIGSEGV_RECOVERY) || defined(HAVE_MACH_EXCEPTIONS)
|
|
// This function handles the badaccess to memory.
|
|
// It is called from the signal handler or the exception handler.
|
|
static bool handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGLIST)
|
|
{
|
|
sigsegv_address_t fault_address = (sigsegv_address_t)SIGSEGV_FAULT_ADDRESS;
|
|
sigsegv_address_t fault_instruction = (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION;
|
|
|
|
// Call user's handler and reinstall the global handler, if required
|
|
switch (sigsegv_fault_handler(fault_address, fault_instruction)) {
|
|
case SIGSEGV_RETURN_SUCCESS:
|
|
return true;
|
|
|
|
#if HAVE_SIGSEGV_SKIP_INSTRUCTION
|
|
case SIGSEGV_RETURN_SKIP_INSTRUCTION:
|
|
// Call the instruction skipper with the register file
|
|
// available
|
|
if (SIGSEGV_SKIP_INSTRUCTION(SIGSEGV_REGISTER_FILE)) {
|
|
#ifdef HAVE_MACH_EXCEPTIONS
|
|
// Unlike UNIX signals where the thread state
|
|
// is modified off of the stack, in Mach we
|
|
// need to actually call thread_set_state to
|
|
// have the register values updated.
|
|
kern_return_t krc;
|
|
|
|
krc = thread_set_state(thread,
|
|
MACHINE_THREAD_STATE, (thread_state_t)state,
|
|
MACHINE_THREAD_STATE_COUNT);
|
|
MACH_CHECK_ERROR (thread_get_state, krc);
|
|
#endif
|
|
return true;
|
|
}
|
|
break;
|
|
#endif
|
|
}
|
|
|
|
// We can't do anything with the fault_address, dump state?
|
|
if (sigsegv_state_dumper != 0)
|
|
sigsegv_state_dumper(fault_address, fault_instruction);
|
|
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
* There are two mechanisms for handling a bad memory access,
|
|
* Mach exceptions and UNIX signals. The implementation specific
|
|
* code appears below. Its reponsibility is to call handle_badaccess
|
|
* which is the routine that handles the fault in an implementation
|
|
* agnostic manner. The implementation specific code below is then
|
|
* reponsible for checking whether handle_badaccess was able
|
|
* to handle the memory access error and perform any implementation
|
|
* specific tasks necessary afterwards.
|
|
*/
|
|
|
|
#ifdef HAVE_MACH_EXCEPTIONS
|
|
/*
|
|
* We need to forward all exceptions that we do not handle.
|
|
* This is important, there are many exceptions that may be
|
|
* handled by other exception handlers. For example debuggers
|
|
* use exceptions and the exception hander is in another
|
|
* process in such a case. (Timothy J. Wood states in his
|
|
* message to the list that he based this code on that from
|
|
* gdb for Darwin.)
|
|
*/
|
|
static inline kern_return_t
|
|
forward_exception(mach_port_t thread_port,
|
|
mach_port_t task_port,
|
|
exception_type_t exception_type,
|
|
exception_data_t exception_data,
|
|
mach_msg_type_number_t data_count,
|
|
ExceptionPorts *oldExceptionPorts)
|
|
{
|
|
kern_return_t kret;
|
|
unsigned int portIndex;
|
|
mach_port_t port;
|
|
exception_behavior_t behavior;
|
|
thread_state_flavor_t flavor;
|
|
thread_state_t thread_state;
|
|
mach_msg_type_number_t thread_state_count;
|
|
|
|
for (portIndex = 0; portIndex < oldExceptionPorts->maskCount; portIndex++) {
|
|
if (oldExceptionPorts->masks[portIndex] & (1 << exception_type)) {
|
|
// This handler wants the exception
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (portIndex >= oldExceptionPorts->maskCount) {
|
|
fprintf(stderr, "No handler for exception_type = %d. Not fowarding\n", exception_type);
|
|
return KERN_FAILURE;
|
|
}
|
|
|
|
port = oldExceptionPorts->handlers[portIndex];
|
|
behavior = oldExceptionPorts->behaviors[portIndex];
|
|
flavor = oldExceptionPorts->flavors[portIndex];
|
|
|
|
/*
|
|
fprintf(stderr, "forwarding exception, port = 0x%x, behaviour = %d, flavor = %d\n", port, behavior, flavor);
|
|
*/
|
|
|
|
if (behavior != EXCEPTION_DEFAULT) {
|
|
thread_state_count = THREAD_STATE_MAX;
|
|
kret = thread_get_state (thread_port, flavor, thread_state,
|
|
&thread_state_count);
|
|
MACH_CHECK_ERROR (thread_get_state, kret);
|
|
}
|
|
|
|
switch (behavior) {
|
|
case EXCEPTION_DEFAULT:
|
|
// fprintf(stderr, "forwarding to exception_raise\n");
|
|
kret = exception_raise(port, thread_port, task_port, exception_type,
|
|
exception_data, data_count);
|
|
MACH_CHECK_ERROR (exception_raise, kret);
|
|
break;
|
|
case EXCEPTION_STATE:
|
|
// fprintf(stderr, "forwarding to exception_raise_state\n");
|
|
kret = exception_raise_state(port, exception_type, exception_data,
|
|
data_count, &flavor,
|
|
thread_state, thread_state_count,
|
|
thread_state, &thread_state_count);
|
|
MACH_CHECK_ERROR (exception_raise_state, kret);
|
|
break;
|
|
case EXCEPTION_STATE_IDENTITY:
|
|
// fprintf(stderr, "forwarding to exception_raise_state_identity\n");
|
|
kret = exception_raise_state_identity(port, thread_port, task_port,
|
|
exception_type, exception_data,
|
|
data_count, &flavor,
|
|
thread_state, thread_state_count,
|
|
thread_state, &thread_state_count);
|
|
MACH_CHECK_ERROR (exception_raise_state_identity, kret);
|
|
break;
|
|
default:
|
|
fprintf(stderr, "forward_exception got unknown behavior\n");
|
|
break;
|
|
}
|
|
|
|
if (behavior != EXCEPTION_DEFAULT) {
|
|
kret = thread_set_state (thread_port, flavor, thread_state,
|
|
thread_state_count);
|
|
MACH_CHECK_ERROR (thread_set_state, kret);
|
|
}
|
|
|
|
return KERN_SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* This is the code that actually handles the exception.
|
|
* It is called by exc_server. For Darwin 5 Apple changed
|
|
* this a bit from how this family of functions worked in
|
|
* Mach. If you are familiar with that it is a little
|
|
* different. The main variation that concerns us here is
|
|
* that code is an array of exception specific codes and
|
|
* codeCount is a count of the number of codes in the code
|
|
* array. In typical Mach all exceptions have a code
|
|
* and sub-code. It happens to be the case that for a
|
|
* EXC_BAD_ACCESS exception the first entry is the type of
|
|
* bad access that occurred and the second entry is the
|
|
* faulting address so these entries correspond exactly to
|
|
* how the code and sub-code are used on Mach.
|
|
*
|
|
* This is a MIG interface. No code in Basilisk II should
|
|
* call this directley. This has to have external C
|
|
* linkage because that is what exc_server expects.
|
|
*/
|
|
kern_return_t
|
|
catch_exception_raise(mach_port_t exception_port,
|
|
mach_port_t thread,
|
|
mach_port_t task,
|
|
exception_type_t exception,
|
|
exception_data_t code,
|
|
mach_msg_type_number_t codeCount)
|
|
{
|
|
ppc_thread_state_t state;
|
|
kern_return_t krc;
|
|
|
|
if ((exception == EXC_BAD_ACCESS) && (codeCount >= 2)) {
|
|
if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS))
|
|
return KERN_SUCCESS;
|
|
}
|
|
|
|
// In Mach we do not need to remove the exception handler.
|
|
// If we forward the exception, eventually some exception handler
|
|
// will take care of this exception.
|
|
krc = forward_exception(thread, task, exception, code, codeCount, &ports);
|
|
|
|
return krc;
|
|
}
|
|
#endif
|
|
|
|
#ifdef HAVE_SIGSEGV_RECOVERY
|
|
// Handle bad memory accesses with signal handler
|
|
static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
|
|
{
|
|
// Call handler and reinstall the global handler, if required
|
|
if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS)) {
|
|
#if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
|
|
sigsegv_do_install_handler(sig);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
// Failure: reinstall default handler for "safe" crash
|
|
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
|
|
SIGSEGV_ALL_SIGNALS
|
|
#undef FAULT_HANDLER
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
* SIGSEGV handler initialization
|
|
*/
|
|
|
|
#if defined(HAVE_SIGINFO_T)
|
|
static bool sigsegv_do_install_handler(int sig)
|
|
{
|
|
// Setup SIGSEGV handler to process writes to frame buffer
|
|
#ifdef HAVE_SIGACTION
|
|
struct sigaction sigsegv_sa;
|
|
sigemptyset(&sigsegv_sa.sa_mask);
|
|
sigsegv_sa.sa_sigaction = sigsegv_handler;
|
|
sigsegv_sa.sa_flags = SA_SIGINFO;
|
|
return (sigaction(sig, &sigsegv_sa, 0) == 0);
|
|
#else
|
|
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
#if defined(HAVE_SIGCONTEXT_SUBTERFUGE)
|
|
static bool sigsegv_do_install_handler(int sig)
|
|
{
|
|
// Setup SIGSEGV handler to process writes to frame buffer
|
|
#ifdef HAVE_SIGACTION
|
|
struct sigaction sigsegv_sa;
|
|
sigemptyset(&sigsegv_sa.sa_mask);
|
|
sigsegv_sa.sa_handler = (signal_handler)sigsegv_handler;
|
|
sigsegv_sa.sa_flags = 0;
|
|
#if !EMULATED_68K && defined(__NetBSD__)
|
|
sigaddset(&sigsegv_sa.sa_mask, SIGALRM);
|
|
sigsegv_sa.sa_flags |= SA_ONSTACK;
|
|
#endif
|
|
return (sigaction(sig, &sigsegv_sa, 0) == 0);
|
|
#else
|
|
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
#if defined(HAVE_MACH_EXCEPTIONS)
|
|
static bool sigsegv_do_install_handler(sigsegv_fault_handler_t handler)
|
|
{
|
|
/*
|
|
* Except for the exception port functions, this should be
|
|
* pretty much stock Mach. If later you choose to support
|
|
* other Mach's besides Darwin, just check for __MACH__
|
|
* here and __APPLE__ where the actual differences are.
|
|
*/
|
|
#if defined(__APPLE__) && defined(__MACH__)
|
|
if (sigsegv_fault_handler != NULL) {
|
|
sigsegv_fault_handler = handler;
|
|
return true;
|
|
}
|
|
|
|
kern_return_t krc;
|
|
|
|
// create the the exception port
|
|
krc = mach_port_allocate(mach_task_self(),
|
|
MACH_PORT_RIGHT_RECEIVE, &_exceptionPort);
|
|
if (krc != KERN_SUCCESS) {
|
|
mach_error("mach_port_allocate", krc);
|
|
return false;
|
|
}
|
|
|
|
// add a port send right
|
|
krc = mach_port_insert_right(mach_task_self(),
|
|
_exceptionPort, _exceptionPort,
|
|
MACH_MSG_TYPE_MAKE_SEND);
|
|
if (krc != KERN_SUCCESS) {
|
|
mach_error("mach_port_insert_right", krc);
|
|
return false;
|
|
}
|
|
|
|
// get the old exception ports
|
|
ports.maskCount = sizeof (ports.masks) / sizeof (ports.masks[0]);
|
|
krc = thread_get_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, ports.masks,
|
|
&ports.maskCount, ports.handlers, ports.behaviors, ports.flavors);
|
|
if (krc != KERN_SUCCESS) {
|
|
mach_error("thread_get_exception_ports", krc);
|
|
return false;
|
|
}
|
|
|
|
// set the new exception port
|
|
//
|
|
// We could have used EXCEPTION_STATE_IDENTITY instead of
|
|
// EXCEPTION_DEFAULT to get the thread state in the initial
|
|
// message, but it turns out that in the common case this is not
|
|
// neccessary. If we need it we can later ask for it from the
|
|
// suspended thread.
|
|
//
|
|
// Even with THREAD_STATE_NONE, Darwin provides the program
|
|
// counter in the thread state. The comments in the header file
|
|
// seem to imply that you can count on the GPR's on an exception
|
|
// as well but just to be safe I use MACHINE_THREAD_STATE because
|
|
// you have to ask for all of the GPR's anyway just to get the
|
|
// program counter. In any case because of update effective
|
|
// address from immediate and update address from effective
|
|
// addresses of ra and rb modes (as good an name as any for these
|
|
// addressing modes) used in PPC instructions, you will need the
|
|
// GPR state anyway.
|
|
krc = thread_set_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, _exceptionPort,
|
|
EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
|
|
if (krc != KERN_SUCCESS) {
|
|
mach_error("thread_set_exception_ports", krc);
|
|
return false;
|
|
}
|
|
|
|
// create the exception handler thread
|
|
if (pthread_create(&exc_thread, NULL, &handleExceptions, NULL) != 0) {
|
|
(void)fprintf(stderr, "creation of exception thread failed\n");
|
|
return false;
|
|
}
|
|
|
|
// do not care about the exception thread any longer, let is run standalone
|
|
(void)pthread_detach(exc_thread);
|
|
|
|
sigsegv_fault_handler = handler;
|
|
return true;
|
|
#else
|
|
return false;
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
bool sigsegv_install_handler(sigsegv_fault_handler_t handler)
|
|
{
|
|
#if defined(HAVE_SIGSEGV_RECOVERY)
|
|
bool success = true;
|
|
#define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
|
|
SIGSEGV_ALL_SIGNALS
|
|
#undef FAULT_HANDLER
|
|
if (success)
|
|
sigsegv_fault_handler = handler;
|
|
return success;
|
|
#elif defined(HAVE_MACH_EXCEPTIONS)
|
|
return sigsegv_do_install_handler(handler);
|
|
#else
|
|
// FAIL: no siginfo_t nor sigcontext subterfuge is available
|
|
return false;
|
|
#endif
|
|
}
|
|
|
|
|
|
/*
|
|
* SIGSEGV handler deinitialization
|
|
*/
|
|
|
|
void sigsegv_deinstall_handler(void)
|
|
{
|
|
// We do nothing for Mach exceptions, the thread would need to be
|
|
// suspended if not already so, and we might mess with other
|
|
// exception handlers that came after we registered ours. There is
|
|
// no need to remove the exception handler, in fact this function is
|
|
// not called anywhere in Basilisk II.
|
|
#ifdef HAVE_SIGSEGV_RECOVERY
|
|
sigsegv_fault_handler = 0;
|
|
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
|
|
SIGSEGV_ALL_SIGNALS
|
|
#undef FAULT_HANDLER
|
|
#endif
|
|
}
|
|
|
|
|
|
/*
|
|
* Set callback function when we cannot handle the fault
|
|
*/
|
|
|
|
void sigsegv_set_dump_state(sigsegv_state_dumper_t handler)
|
|
{
|
|
sigsegv_state_dumper = handler;
|
|
}
|
|
|
|
|
|
/*
|
|
* Test program used for configure/test
|
|
*/
|
|
|
|
#ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <fcntl.h>
|
|
#include <sys/mman.h>
|
|
#include "vm_alloc.h"
|
|
|
|
static int page_size;
|
|
static volatile char * page = 0;
|
|
static volatile int handler_called = 0;
|
|
|
|
static sigsegv_return_t sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
|
|
{
|
|
handler_called++;
|
|
if ((fault_address - 123) != page)
|
|
exit(1);
|
|
if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
|
|
exit(1);
|
|
return SIGSEGV_RETURN_SUCCESS;
|
|
}
|
|
|
|
#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
|
|
#ifdef __GNUC__
|
|
// Code range where we expect the fault to come from
|
|
static void *b_region, *e_region;
|
|
#endif
|
|
|
|
static sigsegv_return_t sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
|
|
{
|
|
if (((unsigned long)fault_address - (unsigned long)page) < page_size) {
|
|
#ifdef __GNUC__
|
|
// Make sure reported fault instruction address falls into
|
|
// expected code range
|
|
if (instruction_address != SIGSEGV_INVALID_PC
|
|
&& ((instruction_address < (sigsegv_address_t)b_region) ||
|
|
(instruction_address >= (sigsegv_address_t)e_region)))
|
|
return SIGSEGV_RETURN_FAILURE;
|
|
#endif
|
|
return SIGSEGV_RETURN_SKIP_INSTRUCTION;
|
|
}
|
|
|
|
return SIGSEGV_RETURN_FAILURE;
|
|
}
|
|
#endif
|
|
|
|
int main(void)
|
|
{
|
|
if (vm_init() < 0)
|
|
return 1;
|
|
|
|
page_size = getpagesize();
|
|
if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
|
|
return 1;
|
|
|
|
if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
|
|
return 1;
|
|
|
|
if (!sigsegv_install_handler(sigsegv_test_handler))
|
|
return 1;
|
|
|
|
page[123] = 45;
|
|
page[123] = 45;
|
|
|
|
if (handler_called != 1)
|
|
return 1;
|
|
|
|
#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
|
|
if (!sigsegv_install_handler(sigsegv_insn_handler))
|
|
return 1;
|
|
|
|
if (vm_protect((char *)page, page_size, VM_PAGE_READ | VM_PAGE_WRITE) < 0)
|
|
return 1;
|
|
|
|
for (int i = 0; i < page_size; i++)
|
|
page[i] = (i + 1) % page_size;
|
|
|
|
if (vm_protect((char *)page, page_size, VM_PAGE_NOACCESS) < 0)
|
|
return 1;
|
|
|
|
#define TEST_SKIP_INSTRUCTION(TYPE) do { \
|
|
const unsigned int TAG = 0x12345678; \
|
|
TYPE data = *((TYPE *)(page + sizeof(TYPE))); \
|
|
volatile unsigned int effect = data + TAG; \
|
|
if (effect != TAG) \
|
|
return 1; \
|
|
} while (0)
|
|
|
|
#ifdef __GNUC__
|
|
b_region = &&L_b_region;
|
|
e_region = &&L_e_region;
|
|
#endif
|
|
L_b_region:
|
|
TEST_SKIP_INSTRUCTION(unsigned char);
|
|
TEST_SKIP_INSTRUCTION(unsigned short);
|
|
TEST_SKIP_INSTRUCTION(unsigned int);
|
|
L_e_region:
|
|
#endif
|
|
|
|
vm_exit();
|
|
return 0;
|
|
}
|
|
#endif
|